Does memory enhancement training alter perceptual representations?

Rhee, Konkle, Brady, & Alvarez

Observers can learn statistical regularities and use them to hold more content in working memory (Brady, Konkle & Alvarez, 2009). Here we investigated whether this memory enhancement fundamentally alters the structure of perceptual representations as measured by a perceptual grouping task.

Memory-Training Task: On each trial, 8 shapes were displayed, followed by a brief delay, and then observers reported the shape that had appeared at a cued location. Shapes were paired such that 80% of the time certain shapes co-occurred (e.g., 'shape A'-'shape B', 'shape C'-'shape D', etc.). After completing 8 blocks of 60 trials, observers nearly doubled the number of shapes they could remember (to 6.5 shapes).

Perceptual-Grouping Task: Observers then performed three blocks of a color repetition detection task that is sensitive to perceptual grouping (Vickery & Jiang, 2009). On each trial, a row of alternating red and green shapes was presented, with one color-repeat along the row. Observers were instructed to detect the color repetition as quickly as possible and then report its location; the shapes were not task relevant and observers were instructed to ignore them. If trained pairs automatically form perceptual groups, then color-repeats within a pair should be more quickly detected than color-repeats across pairs. Additionally, to measure any pair-learning effects during the grouping task, we included a new set of "untrained pairs".

In the first block, observers detected color-repeats faster when they occurred within pairs than between pairs for trained pairs (~51.2 ms difference, p=.02), but not for untrained pairs (p>.05). The within vs between difference for trained pairs was not present after the first block of test trials.

Thus, learning arbitrary shape pairs through a memory training task affects performance in a basic perceptual task, suggesting that this training may give rise to fundamental changes in perceptual representations.

Rhee, J., Konkle, T., Brady, T. F., & Alvarez, G. A. (2012). Does memory enhancement training alter perceptual representations?. Poster presented at the annual meeting of the Vision Sciences Society, May 11-16, Naples, FL.